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1.
西北干旱区分布的巨大内陆盆地,如准噶尔、塔里木、柴达木盆地和河西走廊等,被认为是典型的戈壁沙漠地区,约占国土总面积的25%。由冰雪融水与降水补给形成的山区河流,流入山前平原,在戈壁带入渗地下,转化为地下水,并在绿洲带溢出地表,成为绿洲耕地的主要灌溉水源。自20世纪50年代以来,由于大规模的水利化建设,导致水资源条件发生巨大变化,生态环境严重恶化,最终导致大片土地荒漠化。因此,重点论述干旱区在人类经济活动影响下,水文系统的演变及其与水环境和生态环境之间的相互影响、相互制约关系。  相似文献   

2.
本文以郑洛地区为研究区域,以裴李岗文化时期、仰韶文化前期、仰韶文化后期和龙山文化时期为时间序列,对研究区域的流域盆地面积与相应的遗址点数量的关系、流域盆地面积与相应的遗址点增长速率的关系,以及各个流域盆地中遗址点分布密度的时空分布特征进行了研究。结果显示:(1)通过相关方法分析,以数字化的形式表明了流域盆地面积与分布的遗址点数量呈显著的正相关关系,且裴李岗文化时期的相关程度与其他3个文化时期相比较小;(2)对各流域盆地内遗址点的变化趋势分析发现,流域盆地面积与分布的遗址点变化趋势呈显著的正相关关系,这也解释了流域盆地黄河流域(B)、伊洛河流域(C)的变化趋势最快的缘由;(3)对各流域盆地内遗址点的分布密度进行分级可发现,在裴李岗文化时期,东部地区遗址点的分布密度大于西部地区,而其他3个文化时期是中西部地区大于东部地区。  相似文献   

3.
Morpho-tectonic study plays an important role in deciphering the effects of tectonic activity in the geomorphic evolution of the drainage basins.Romushi watershed forms one of the major watersheds of the intermontane Karewa Basin of Kashmir Valley.The Karewa sediments are characterized by glacio-fluvio-lacustrine deposits capped by the aeolian loess.The geomorphic,morphometric and lithostratigraphic studies of these cap deposits have been carried out to elucidate the effect of tectonics on the geomorphic evolution of Romushi Watershed.Geomorphic mapping was carried out using GPS measurements,DEM at 30m resolution,Topographic Position Index(TPI) model,topographic maps,LANDSAT TM Imagery and field data.Morphometric and morphotectonic analyses in GIS environment were used to calculate various geomorphic indices(Mountain Front Sinuosity Index,Bifurcation Ratio,Asymmetry Factor,River Profile,etc).These indices reveal that the tectonic uplift observed in the region due to Himalayan orogeny coupled with mass movement and aeolian deposition have dominated the landscape evolution of intermontane Karewa Basin of Kashmir throughout the Late Quaternary Period.Additional data from lithostratigraphic measurements were analyzed to understand the geomorphic evolution of intermontane Karewa Basin.The data revealed that the basin has experienced differential uplift and erosion rates from time to time in the geological past.This was corroborated by the results from the morphometric and morphotectonic analysis.  相似文献   

4.
WATERRESOURCESTRANSFORMATIONANDWATERQUALITYVARIATIONINTHEURUMQIRIVERBASINQuYaoguang(曲耀光);LuoHongzhen(骆鸿珍)(LanzhouInstituteofG...  相似文献   

5.
中国及境外天山铅锌矿床多有发现,如哈萨克斯坦Tekeli、Shalkiya和Achisai,乌兹别克斯坦Kurgashinkan和Uchkulach,塔吉克斯坦Altyntopkan,中国新疆乌拉根、彩霞山、阿齐山、阿尔恰勒等大型—超大型铅锌矿床,构成了天山巨型铅锌成矿带。这些铅锌矿床形成于怎样的地球动力学背景?铅锌成矿的基本地质特征是什么?有哪些重要成矿类型?受何要素控制?未来找矿突破方向在哪里?这些都是颇受关注的地质找矿问题。在广泛矿产地质调查和综合分析前人研究成果的基础上,将中国及境外天山作为整体,综述了天山造山带构造演化和重要铅锌成矿环境、典型矿床特征与成矿系统/成矿类型,总结了天山地区铅锌成矿演化过程,并分析了区域铅锌成矿特点与找矿突破方向。结果表明:天山造山带经历了前寒武纪古陆形成、洋-陆俯冲增生、陆-陆碰撞造山和陆内成盆4个地球动力学过程,先后出现了元古宙古陆边缘裂陷盆地、古生代洋-陆俯冲增生岛弧、晚古生代陆-陆碰撞造山与中—新生代山前/山间盆地4类重要铅锌成矿环境。在元古宙古陆边缘裂陷盆地环境,主要受同生断层、还原性细碎屑岩-碳酸盐岩建造等控制,形成了古陆边缘裂陷盆地铅锌成矿系统与SEDEX型铅锌矿床;在古生代洋-陆俯冲增生岛弧环境,主要受弧岩浆活动、断裂构造、地层等控制,形成了增生岛弧铅锌成矿系统与矽卡岩型、斑岩型、岩浆热液脉型、VMS型铅锌矿床;在晚古生代陆-陆碰撞造山环境,主要受被动陆缘海相碳酸盐岩、张性开放空间、逆冲推覆构造等控制,形成了碰撞造山铅锌成矿系统与MVT型铅锌矿床;在中—新生代山前/山间盆地环境,主要受盆地三元结构、油气运移与红层“漂白”、硫酸盐岩等控制,形成了山前/山间盆地铅锌成矿系统与砂岩型铅锌矿床。由此可见,天山地区存在多种铅锌成矿环境和不同铅锌成矿系统与成矿类型,其铅锌成矿表现出长时间、多期次、多类型叠合成矿和一定继承性的演化特点。尽管沉积岩容矿铅锌矿床(包括SEDEX型、MVT型和砂岩型)在全球铅锌矿产资源中占据主导地位,而在天山地区增生岛弧铅锌成矿系统则占有更为重要的地位,特别是北天山岛弧带,哈萨克斯坦—伊犁板块南、北缘和中天山地块应该给予高度重视。与此同时,哈萨克斯坦—伊犁板块北缘与东天山中天山地块元古界SEDEX型铅锌找矿、境外中天山地块北缘与南天山造山带古生代被动陆缘碳酸盐岩地层MVT型铅锌找矿、新疆西南天山山前/山间盆地砂岩型铅锌找矿前景良好,也仍值得持续关注。  相似文献   

6.
1 INTRODUCTION The Ussuri / Wusuli River watershed is located in the southeast part of Heilongjiang Province of China, which joins remote regions of Russia. The watershed consists of approximately 26 000 000 ha, which is about two thirds of the watershed ecosystem in Russia, one  third in China. The Ussuri River forms part of the border between Russia and China, the shared border stretches more than 1100 km. Khanka/Xingkai Lake lies within both China and Russia. Its total area …  相似文献   

7.
The Wenchuan Earthquake of May 12,2008 triggered large numbers of geo-hazards.The heavy rain on 13 August 2010 triggered debris flows with total volume of more than 6 million cubic meters and the debris flows destroyed 500 houses and infrastructure built after the Wenchuan Earthquake.The study area Qingping Town was located in the northwestern part of the Sichuan Basin of China,which needs the second reconstructions and the critical evaluation of debris flow.This study takes basin as the study unit and defines collapse,landslide and debris flow hazard as a geo-hazard system.A multimode system composed of principal series system and secondary parallel system were established to evaluate the hazard grade of debris flow in 138 drainage basins of Qingping Town.The evaluation result shows that 30.43% of study basins(42 basins) and 24.58% of study area,are in extremely high or high hazard grades,and both percentage of basin quantity and percentage of area in different hazard grades decrease with the increase of hazard grade.According to the geo-hazard data from the interpretation of unmanned plane image with a 0.5-m resolution and field investigation after the Wenchuan Earthquake and 8.13 Big Debris Flow,the ratio of landslides and collapses increased after the Wenchuan Earthquake and the ratios of extremely high or high hazard grades were more than moderate or low hazard grades obviously.23 geo-hazards after8.13 Big Debris Flow in Qingping town region all occurred in basins with extremely high or high hazard grades,and 9 debris flows were in basins with extremely high hazard grade.The model of multimode system for critical evaluation could forecast not only the collapse and landslide but also the debris flow precisely when the basin was taken as the study unit.  相似文献   

8.
河源区边界是重要的国家基础地理信息之一,但除长江、黄河等大江大河外的我国大部分其他中小流域仍缺乏确切的河源区边界信息,需要科学划定河源区边界以支持流域水生态保护相关政策的规划与实施。对此,本文在确立河源区划分原则、明确划分依据的基础上,提出了基于多特征指标和层次聚类分析法的河源区边界划定方法。以沁河流域为研究案例,首先利用均值变点分析法计算沁河流域子流域提取的最佳汇流累积量分位数阈值为0.15%,再基于子流域的多特征指标运用层次聚类分析法最终确定河源区范围边界,并将该方法应用于长江、黄河流域进行验证分析。结果表明:① 基于多特征指标和层次聚类分析提取的沁河流域河源区范围处于河底比降法、水文站点方法得到的源区范围面积之间;② 该方法在长江、黄河流域河源区划分结果的交并比分别达到85.40%和79.99%,侧面验证了本文方法进行河源区边界划分的合理性与适用性。基于多特征指标和层次聚类分析的河源区边界自动划分方法可以简捷高效地识别缺乏明确河源区边界信息的流域河源区范围,为我国河源区生态安全屏障识别、水资源保护相关政策的规划和实施提供科学支撑。  相似文献   

9.
The key aspect in planning and management of water resources is to analyze the runoff potential and erosion status of the river basin. For the detailed investigation of hydrological response, freely available Cartosat-1 (IRS-P5) data was used for the preparation of digital elevation model (DEM). The runoff potential and type of erosive process of 22 river basins originating in the global biodiversity hotspot of Western Ghats, was inferred through hypsometric analysis. Several parameters like Hypsometric integral (HI), maximum concavity (Eh), coordinates of slope inflection point (I) given by a* and h* and normalized height of hypsometric curve (h) were extracted from the hypsometric curves and used for understanding the hydrological responses. From the hypsometric curves, the landform evolution processes were inferred. Contribution of diffusive and fluvial processes in slope degradation of the river basins was understood. Basins with lesser area (<100 km2) were found to have a positive correlation between hypsometric integral and basin area, whereas for large basins no such correlation exists. Based on the study, river basins can be prioritized for the appropriate conservation measures.  相似文献   

10.
本文系统研究了羌塘盆地查郎拉地区中、新生代的构造特征,将整个研究区划分为五个构造单元。即那日- 破曲褶皱带、江达- 杜日断褶带、塞仁那来- 巴陇复式向斜断褶带、气相错- 查巴断陷带、查曲公玛- 日昂巴山间盆地。从晚三叠世以来,图幅内经历了印支期、燕山期、喜山期构造运动,印支期主要是在图幅北部上三叠统地层中形成北东向褶皱,燕山运动早期本区构造活动最为强烈,形成了全区范围内的东西向褶皱和断层,其中尤以南部塞仁那来- 巴陇复式向斜断褶带最为强烈,构造最为紧密,燕山晚期,以断陷构造为主,形成中部的查曲公玛- 日昂巴山间盆地和南部的气相错- 查巴断陷带,喜山期主要是形成一些新构造活动。  相似文献   

11.
Petroleum geological framework and hydrocarbon potential in the Yellow Sea   总被引:2,自引:0,他引:2  
Sedimentary basins in the Yellow Sea can be grouped tectonically into the North Yellow Sea Basin (NYSB), the northern basin of the South Yellow Sea (SYSNB) and the southern basin of the South Yellow Sea (SYSSB). The NYSB is connected to Anju Basin to the east. The SYSSB extends to Subei Basin to the west. The acoustic basement of basins in the North Yellow Sea and South Yellow Sea is disparate, having different stratigraphic evolution and oil accumulation features, even though they have been under the same stress regime since the Late Triassic. The acoustic basement of the NYSB features China-Korea Platform crystalline rocks, whereas those in the SYSNB and SYSSB are of the Paleozoic Yangtze Platform sedimentary layers or metamorphic rocks. Since the Late Mesozoic terrestrial strata in the eastern of the NYSB (West Korea Bay Basin) were discovered having industrial hydrocarbon accumulation, the oil potential in the Mesozoic strata in the west depression of the basin could be promising, although the petroleum exploration in the South Yellow Sea has made no break-through yet. New deep reflection data and several drilling wells have indicated the source rock of the Mesozoic in the basins of South Yellow Sea, and the Paleozoic platform marine facies in the SYSSB and Central Rise could be the other hosts of oil or natural gas. The Mesozoic hydrocarbon could be found in the Mesozoic of the foredeep basin in the SYSNB that bears potential hydrocarbon in thick Cretaceous strata, and so does the SYSSB where the same petroleum system exists to that of oil-bearing Subei Basin.  相似文献   

12.
水系沉积物地球化学测量是卓有成效的找矿技术方法, 基于汇水盆地的水系沉积物地球化学异常提取有助于追溯异常源头、指明找矿方向。基于SCB法提出了汇水盆地法, 该方法以自然汇水盆地为预测单元, 将各样品点的地球化学属性特征赋予各自所在区域, 预测结果较为符合地形地貌特征, 且对于采样密度较高的1∶5万水系沉积物地球化学测量数据有较好的应用效果。以东昆仑乌拉斯太地区为研究区, 使用高精度DEM划分汇水盆地, 利用该方法对1∶5万水系沉积物Au、Ag、Pb因子得分进行了异常信息提取, 在提取过程中利用多种地貌参数(干流坡度、地形起伏比、汇水盆地面积)作为泥沙输移比进行残差校正计算, 并在此基础上, 利用C-A分形法分离了地球化学背景与异常。异常提取结果表明, 汇水盆地面积参数最适合用作乌拉斯太地区的泥沙输移比参与顺流衰减校正, 使用汇水盆地法可以有效识别和提取该地区地球化学异常信息。使用汇水盆地法提取的化探异常范围与矿床空间位置吻合度高, 可以为进一步找矿工作提供有利的信息。   相似文献   

13.
Based on recent year's advances in geothermal resources studies and explorations in China, this paper reviews the basic distributive characteristics of hot springs in the uplifted area and geothermal water in the Meso-Cenozoic sedimentary basins, suggests that two hydrothermal activity concentrated zones (South Tibet Autonomous Region - West Sichuan Province - West Yunnan Province and coastalarea of Southeast China), one large basin(North China Basin) and two smaller basins(Weihe Basin and Leiqiong Basin) are major areas of study and exploration of geothermal resources in China continent, considers that geothermal resources in China have certain potential of exploitation and should be used, but the scale of exploitation seems to be limited, they cannot occupy an important position in energy supply and can only be regarded as a supplementary energy source.  相似文献   

14.
二连盆地群是内蒙古自治区最大的一个晚中生代盆地群,都呼木盆地是其中之一富煤盆地,含煤层位于白垩纪彦花组第五段,煤层的煤质为中灰、中高硫、高发热量、低磷—中磷低氯的褐煤,受好来-锡林呼都格断裂控制形成的赛罕塔拉煤田,自然分割成了若干个规模不等的聚煤盆地。盆地边缘地区岩浆岩发育,以华力西中晚期、燕山早期侵入岩为主,岩性从超基性—酸性,一般呈岩基产出。煤层形成于漫流为主的沉积组合类型和浅水重力流和泥炭沼泽沉积物为主的沉积相。沉积环境对富煤带展布起控制作用,该区主要聚煤作用发生在盆地发育的晚期,富煤带在控盆断裂的西北一侧2~4km附近。  相似文献   

15.
基于ArcView GIS平台,利用流域水资源规划管理软件工具MIKE BASIN,以西藏达孜县为试验区,采用50×50m格网DEM数据,开展拉萨河流域内的地表水的产汇计算,并进行流域水资源合理配置研究。本文建立了流域供需水的空间分析网络,对各汇流区进行流域模拟分析,研究结果以直观的专题图表显示,为本区的流域水资源管理提供了可视化的研究框架。  相似文献   

16.
One of the most vulnerable parts to natural hazards in Serbia is Kolubara river basin. In the past, during the period from 1929 to 2013, 121 torrential flood events in the Kolubara river basin were recorded which show that this territory is extremely vulnerable to the torrential floods. The extreme event which occurred in May 2014 causing the catastrophic material damages and casualties was the latest and historical flood. The analysis of natural conditions in the Kolubara basin uniformly showed that this area is predisposed to a greater number of torrential floods due to its geomorphological, hydrological and land use properties. Torrential floods are closely related to the intensity and spatial distribution of erosive processes in the upper part of the Kolubara basin. The estimation of soil erosion potential is generally achieved by Erosion Potential Model (EPM). For the purposes of determining the degree of torrential properties in various water streams in the Kolubara basin, the calculation of susceptibility to torrential floods was assessed by Flash Flood Potential Index (FFPI). More than half of the basin area (57.2%) is located within the category of very weak and weak erosion (Zsr = 0.35), but the category of medium erosion is geospatially very common. Such a distribution of medium erosion category provides conditions for generating, i.e. production of sediment which would boost torrential properties of water streams. After the classification of the obtained FFPI values it was determined that 25% of the Kolubara basin is very susceptible to torrents and this data should be seriously taken into consideration. Based on the analyses, the best and most successful manner of defence is prevention which consists of the integrated river basin management system (integrated torrent control system) so that technical works in hydrographic networks of torrents and biological and biotechnical works on the slope of the basin would be the best solution. Permanent control of erosive and torrential processes in the river basin will be not only important for flood control but it can also protect the existing and future water reservoirs and retentions from siltation with erosion sediment which is of great significance to the water management, agriculture, energy sector, and the entire society.  相似文献   

17.
根据垂直形变资料分析,北天山山前地带的垂直形变具有继承性运动特征,天山山体继续上升,盆地继续下降,在空间上具有统一性,在时间上具有同步性。1980年天山北缘石河子南5.8级地震,震前的正向加速形变转为反向形变,为预报北天山地震带的强震提供了时间依据;反向形变异常最大的地段,是未来发生强震的可能地点。  相似文献   

18.
运用沉积学理论,结合岩相组合、岩石类型及沉积建造标志,研究大杨树盆地九峰山组沉积体系特征及时空配置关系.结果表明:研究区发育冲积扇、冲积平原、三角洲平原及河流沉积体系.九峰山组下段沉积时期,湖泊体系最为发育,以湖泊体系为中心发育小范围的三角洲平原、冲积平原和冲积扇,物源来自北部及东侧的盆地边缘隆起带;九峰山组上段沉积时期受盆地内火山活动及大兴安岭隆起影响,湖泊体系整体向南退却,三角洲平原、冲积平原及冲积扇体系范围逐渐扩大,为九峰山组最主要的聚煤时期,物源来自盆地两侧及北部隆起地带.该研究为大杨树盆地九峰山组资源勘探提供指导.  相似文献   

19.
长期以来,我国采用分类管理的方式管理不同类型的自然资源,在自然资源监测监管中造成了部分自然资源重复统计、权属不明等问题,在湿地、林地等自然资源中表现尤其明显。为了系统性地进行自然资源监测监管,需要对自然资源进行整体性地、统一性地分类,建立一个综合性的自然资源分类体系。本文遵循“山水林田湖草”是一个生命共同体的理念,从这一理论思想出发,整理单门类自然资源整体和个体之间的关系,分析国内外的分类编码体系,从法理、学理和管理不同角度研究整理自然资源分类现状,综合考虑地表覆盖层的监测监管要求,采用树状分类法和交叉分类法重新构建了三级分类的自然资源分类体系框架,为构建自然资源监测监管体系提供必要的基础支撑,为完善生态文明建设,为国民经济健康持续发展提供重要的基础保障。  相似文献   

20.
Southeast China coastal areas belong to subtropical monsoon climatic zone,thus easily affected by floods resulted from typhoons and rainstorm.Since the areas of river basins are small,rivers flood regulation capacities are low,and therefore flood hazard is grave.In the paper,taking the Yongjiang basin in southeast China as an example,the approaches and methods of geographic information system(GIS) applied to flood disaster control and reduction research on small basin are explred.On GIS help the rainfall-runoff calculation model and the river dchannel flood routing model are developed.And the evaluating flood submerged are and the damage assessment models are built supported by digit elevation models.Lastly the decision support system on GIS supported for flood control in research basin has been set up.This greatly improves flood-proofing decision-making capacities in river basin,and provides valuable information and a mode for flood prevention and reduction in the medium and small basin .Meanwhile,the research indicates that technologies of GIS provide a powerful tool for flood disaster control.  相似文献   

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